People are constantly improving the speed and reliability at which communications are carried out. As technology makes more and more information available, people have a need to disseminate information to one another quickly. People also want to know that the information is received shortly after it has been sent.
Attention recently has been directed to implementing communication services over the worldwide network now commonly known as the Internet. The Internet had its genesis in U.S. Government funded research (called ARPA) which made possible national internetworked communication systems. This work resulted in the development of network standards as well as a set of conventions for interconnecting networks and routing information. These protocols are commonly referred to as TCP/IP. The protocols generally referred to as TCP/IP were originally developed for use only through Arpanet, however, they have subsequently become widely used. TCP/IP is flexible and robust, in effect, TCP takes care of data integrity and IP moves the data.
The Internet basically comprises several large computer networks joined together over high-speed data links ranging from ISDN to T1, T3, FDDI, SONET, SMDS, OT1, etc., and provides two broad types of services: connectionless packet delivery service and reliable stream transport service. The most prominent of these national networks are MILNET (Military Network), NSFNET (National Science Foundation NETwork), and CREN (Corporation for Research and Educational Networking). An estimated 242 million people were connected to the Internet as of 1999 according to CommerceNet™ a Silicon Valley, California based organization composed of over 600 companies and organizations worldwide.
A simplified diagram of the Internet is depicted in FIG. 1. Generally speaking the Internet 50 consists of Autonomous Systems (AS) which may be owned and operated by Internet Service Providers (ISPs) such as PSI, UUNET, MCI, SPRINT, etc. Three such AS/ISPs are shown in FIG. 1 at 52, 54 and 56. The Autonomous Systems (ASs) are linked by Inter-AS Connections 58, 60 and 62. Information Providers (IPs) 64 and 66, such as America Online (AOL) and Compuserve, are connected to the Internet via high speed lines 68 and 70, such as T1/T3 and the like. Information Providers generally do not have their own Internet based Autonomous Systems but have or use Dial-Up Networks such as SprintNet (X.25), DATAPAC and TYMNET.
By way of illustration, MCI is both an ISP and an IP, Sprint is an ISP, and MicroSoft (MSN) is an IP using UUNET as an ISP. Other information providers, such as universities, are indicated in exemplary fashion at 72 and are connected to the AS/ISPs via the same type connections, here illustrated as T1 lines 74. Corporate Local Area Networks (LANs), such as those illustrated in 76 and 78, are connected through routers 80 and 82 and links shown as T1 lines 84 and 86. Laptop or PC computers 88 and 90 are representative of computers connected to the Internet via the public switched telephone network (PSTN), shown connected to the AS/ISPs via dial up links 92 and 96.
The information providers (IPs) are end systems that collect and market the information contained on the Internet through their own servers. Internet service providers (ISPs) are companies such as UUNET, PSI, MCI and SPRINT that transport the information, and market the usage of their networks. Hereinafter, ISP and Internet service provider will be used to refer to both ISPs and to IPs collectively, as both provide Internet access for subscribers.
Initially, ISPs merely provided access to the information available on the Internet to their subscribers. However, it was quickly recognized that messages could be sent between computers having access to the Internet. It was also recognized that a message could be stored on an intermediate computer for later delivery to a computer that was not connected to the Internet at the time the message was sent, but would later become connected to the Internet. Internet service providers began offering electronic mail (e-mail), enabling their subscribers to communicate by sending messages to one another as well as to other people with access to the Internet. Increasingly, people began using the Internet to communicate with one another, and began searching for faster modes of communication via the Internet.
The next advance in Internet communications related to popup message windows. By knowing that someone is connected to the Internet and the address of his or her computer, it is possible to open a window and send a copy of the window that opens on his or her screen. Typically, the original window and the copy are split into two parts, each part having its own functionality. One part of the original window allows the sender to type a message and transmit the message to a remote computer. Correspondingly, one part of the copy window allows the receiver to type a message and transmit the message to the same remote computer. The second part of each window is linked to the remote computer and receives all the typed messages and displays them on both the sender's screen and the receiver's screen so that both persons are able to read what the other has typed. An improvement of pop-up message windows is to provide voice grade transmissions from one computer to another via the Internet, much like a standard telephone call. Again, the sender of the voice call must know whether the intended recipient is connected to the Internet. As a result of these developments, many ISPs allow subscribers to specify addresses, i.e., an e-mail address, that a subscriber would like to be notified about when the address is actively connected to the Internet. In turn, when an ISP recognizes that a subscriber is connected to the Internet, the ISP looks at the various other Internet users specified by the subscriber and sends notification and a corresponding Internet protocol address if any of the other Internet users are actively connected to the Internet. If an actively connected Internet address that the subscriber has been notified about disconnects from the Internet, then the ISP removes notification from the subscriber's computer so that the subscriber knows that the particular Internet user using the Internet address is no longer available to receive communications via a pop-up message window or voice communications over the Internet.
Rapid advances have also been made concerning wireless communications, especially regarding the emergence of digital cellular telephones. Many new wireless communications devices and related services have emerged that allow people to communicate freely as they roam, without the need for a fixed network connection. In particular, modern digital public wireless telephone networks offer customers a wide range of communication services combined with a high degree of mobility. These services encompass sending and receive sophisticated voice, data and messaging services through a cellular or PCS network.
Wireless telephone communication systems supporting such services evolved from the Advanced Mobile Phone Service (AMPS) technology, introduced around 1983, to the more sophisticated digital-based air interface protocols. Digital access technologies include Time Division Multiple Access (TDMA) and Code Division Multiple Access (CDMA) schemes.
An exemplary digital cellular network 3 (depicted in FIG. 2) includes a number of mobile switching centers (MSCs) 11, only one of which appears in the drawing for simplicity of illustration. Each MSC 11 connects through trunk circuits to a number of base stations 13, which the MSC controls. Through the MSC 11 and the base stations 13, the network 3 provides voice-grade digital telephone services over the common air interface to and from the digital telephones 5. The network elements also provide data services over the logical communication channels, such as signaling channels used to keep track of digital telephones 5, and paging channels used to send data to and from digital telephones 5.
The digital telephones 5, the MSCs 11 and the base stations 13 implement one or more standard air-link interfaces. For example, the wireless telephone network 3 may support dual-mode services. Although not shown separately, such a dual-mode network includes wireless telephone components that output analog telephone signals for transmission according to an analog wireless protocol (e.g., AMPS) as well as digital wireless system components that operate in accord with a digital wireless protocol, for example the CDMA protocol IS-99. The base stations may provide both types of services. Alternatively, the network may comprise base stations that send and receive voice and signaling traffic according to the prescribed analog protocol as well as digital base stations that utilize the digital wireless protocol. Each dual-mode MSC typically includes a switching subsystem for analog telephone services, a switching subsystem for digital telephone services, and a control subsystem. Other MSCs may implement only one type of service.
The wireless network 3 includes a home location register (HLR) 15 that stores subscriber profiles for each of the wireless subscribers and their associated digital wireless telephones 5. The HLR 15 may reside in the home MSC 11 or in a centralized service control point that communicates with the MSC(s) 11 via an out-of-band signaling system such as an SS7 network. As recognized in the art, the HLR 15 stores for each mobile subscriber certain data such as the subscriber's mobile telephone number, the mobile identification number, the power status of her mobile telephone, information specifying what base stations 13 the subscriber is nearest, and the wireless services subscribed to by the mobile subscriber, such as numeric paging or text-based paging, data communication services, etc. The HLR 15 typically stores this information in tables contained within a database containing a record relating to each cellular telephone. Cellular telephone records are often updated, for example, when new services are subscribed to, when the subscriber powers on his or her digital telephone 5, or when the subscriber moves about causing his or her digital telephone 5 to de-register and register with various base stations 13. Additional information, for example power-off status, is also received and updated for digital telephones. The updated information in the HLR 15 informs the wireless network 3 of the current status of each digital wireless telephone 5, i.e., whether a particular digital telephone is powered on so that it may receive a call, what base station 13 to route the call to in order to reach the particular digital telephone 5, and what services are available during the call to or from the particular digital telephone 5.
Being readily available for contact has become increasingly important for a growing number of people who have a significant need to be reachable regardless of their location. Many such persons have a telephone for business, a telephone for home, a mobile cellular telephone in the car, a transportable telephone for personal carrying, as well as stations providing telephone service through computers. Business people and professionals at times have multiple offices and may additionally work at a home office. All of these telephones and computer stations generally have different telephone numbers and Internet addresses. This requires a caller to know or look up multiple numbers and addresses, and frequently to make multiple calls in order to reach a person, especially if the person's cellular telephone that is carried by that person is off.
A specific problem with current technology is that other than the ability to send a short e-mail message from an Internet user to a digital telephone, there is no communication link between Internet users and digital telephone users. Currently, people have no way of knowing whether the cellular telephone of someone they wish to contact is powered on or is off. It would be an asset to know the power status of an individual's cellular telephone so that someone could quickly determine whether that individual could be contacted via his or her cellular telephone.